I am very happy with my GLA-1000.
It is a simple little desk top amp that runs on 110 that gets the job done. Mine is on its second set of tubes in 20+ years and easily puts out 500 Watts PEP. There is an easy mod to replace the tubes with EL509s incase these sweep tubes get too expenisve.
The amp doesn't have a tuned input - but since my exciter has a built in antenna tuner- I just use that. Some other reviews have said it is hard to tune and has a loud fan. I don't find either of those things to be true of mine. If you see this amp for under $300.00 I would buy it. If it is over $300.00 - you may be able to buy more amp for your money with other models.

This conversion amp by N8GPQ is great. It is a carefully thought out conversion that looks clean and works great. There is a website that shows pictures of how the conversion is done and there are circuit boards available for the new caps and voltage doubler. I am completely satisfied with mine. I drive mine with about 40 watts and the cabinet hardly gets warm. This tube has a high gain. Make sure you don't overdrive it.

Dont do the converstion, contary to what some here think, if you do it, you end up and have to modify the rf board, by dropping it ever so slightly, or they wont fit inside the case, and by doing so, the bottom of the tubes dont get cooled by the fan!! And you WILL end up cracking them.... If you do the mod, get GE 6kg6a's.. they are not as tall, and they are as tough as the russian tubes, and will put out the same amount of power.....

I purchased my GLA-1000 at a hamfest in October for $200. The fellow had LOTS of amps and radio gear, and wasn't concerned with sqeezing every dime out of the older stuff. The amp was 10 cosmetically and the seller said that he "upgraded" the finals. I haven't opened the hood to see exactly what he did, but the amp does have two tubes, so maybe just a new set of 6's? Anyway, it took just a few minutes to connect it to my Yaesu 920 and tune it up. I expected 300-500 W output on peaks, I am seeing (confirmed with several different swr/pwr meters) typically, 500-1000 W out, depending on the band.
Now, when I operate, I'm using my amp about 50% of the time. It runs VERY cool and appears to produce no spatter or spurs. This is my first amp and I have to say I must have stumbled on one that somebody spent some extra TLC on. If you find one for sale that's clean and operational, you'll have a pretty good little amp that makes a nice addition to the HF station.

I have done numerous conversions on the GLA-1000 amps and they all work great. Rebuilding an amp is not only fun but educational and you don't need to have previous technical experience to do this. There are also numerous websites on this and hams who are more than willing to help out. The GLA-1000 is a great amp with a small footprint, easy to convert, and reliable. Tubes and parts are found easily on the internet.

Forget all the converstions! You end up wasting a lot of time to gain nothing. I bought the Far circuit boards and EL509's, and waisted a lot of my time! Now, I am going to do it right, and put all the original back into it, and throw away the junk I bought!

This review is of a Dentron GLA-1000B that has been converted to use a single GI-7B Russian ceramic/metal triode. There is a wealth of information on the internet about this conversion and the data is growing rapidly. The best place to start to gather this information is http://www.geocities.com/ko4nrbs/ This site will link to several others pertaining to this and similar conversions.

My amplifier was converted by N8GPQ. He did a superb job and the end result is a thoroughly up-to-date amplifier that puts out 600 watts very reliably on 80 through 10 meter bands.

The conversion includes several modifications to the original circuitry of the amplifier which correct some issues with the amp as well as circuit changes and physical modifications to enable the use of the GI-7B tube.

I have tested the amplifier on all bands and have not had a single problem with it's operation. It is extremely easy to tune and is driven to maximum power with about 55 watts of drive. Audio reports are excellent on all bands.

The performance I am getting out of this amplifier coupled with the small desktop footprint is just a fantastic combination. I have had a blast operating it and am so convinced of it's reliablity that I have begun gathering parts necessary to build up another just like it.

Other amplifiers have been converted to use 1 or more of these inexpensive tubes (SB-230, MLA-2500, L-4B). Take a look at the data and give it a try. You'll love the results.

Puts out a respectable 400-500W on peaks. Gets you through the mud when the going is a little tough. I use a pulser to tune it into a cantenna, and the tubes should last a LONG time. 6LQ6's are not all that hard to find since Ebay came along! Small footprint helps if your shack is small. Overall a good value for around $300.